In a motor control technology, it is necessary to detect a rotational position of a rotary shaft of a motor in order to obtain a positional deviation between a position command and an actual rotational position of the rotary shaft. One position detector is a resolver. Here, in the case of using the resolver, a position correction technology in consideration of a position detector error of the resolver is necessary. Accordingly, in devices disclosed in Japanese Patents No. 2541169 and 5281102, correction data is stored in a memory in advance, a corrected position signal is generated by correcting a position detection signal generated based on a signal output from the resolver by the correction data and the motor is feedback-controlled using this corrected position signal during a motor control.